Bear in mind that most of us here are either patients or caregivers, not medical personnel. The high limit for CA19-9 is 35 so you are within the range of normal. I actually know one of the researchers who developed the CA19-9 test and measurement. There's no magic to the "35" number. It is 2 standard deviations in the reading when a test sampling of normal test recipients get the CA19-9 test. Your CA19-9 shouldn't be a worry unless you're doctor sees other issues.

If your gastroenterologist is like my wife's, a high alk-phos is a concern. My wife's gets very high while in chemo and it slowly returns to a better range when she has extended breaks from treatment. He's never offered an option other than getting off chemo which of course isn't an option for my wife.